From my blog:

Bruce Schneier: “The FBI’s demands are specific to one phone, which might make its request seem reasonable if you don’t consider the technological implications: Authorities have the phone in their lawful possession, and they only need help seeing what’s on it in case it can tell them something about how the San Bernardino shooters operated. But the hacked software the court and the FBI wants Apple to provide would be general. It would work on any phone of the same model. It has to.”